<!DOCTYPE html>

<html>
    <head>
        <meta charset="UTF-8">
        <title>测试框架</title>
        <script src="kaifamiao.js"></script>
    </head>
    <body>

        <button>我是按钮</button>
        
        <script>
            (()=>{
                $('button').once( 'click', evt => {
                    console.log(evt.type, evt.target);
                });
            })();
        </script>
    </body>
</html>